[unreadable] As a junior faculty member at the University of California, San Francisco, Daniel Ciccarone, MD, MPH, has begun exploring the medical consequences of the use of black tar heroin. Through mentoring relationships, course work, structured tutorials and development of a research program, Dr. Ciccarone will advance his independence in conducting patient-oriented clinical research. [unreadable] [unreadable] The consequences of heroin use have long been documented. However, little attention has been given to the medical consequences of the specific type of heroin used. Heroin exists in two major morphologies in the United States. Black tar heroin (BTH), the form of heroin that predominates in the Western U.S., has been associated with soft tissue infections including abscesses, necrotizing fasciitis and various clostridial infections. BTH use may also account for the lower HIV prevalence among IDUs in the Western U.S. Behavioral patterns and health outcomes associated with the use of specific heroin types deserves further exploration. [unreadable] [unreadable] Study sites will include San Francisco, California and Hartford, Connecticut. Ethnographic study of street-based injection drug users (IDUs) will examine injection related behaviors including drug acquisition, storage, preparation, use and hygiene. Indigenous beliefs related to disease and specific heroin use will be explored. A survey instrument will be developed using results from the ethnographic study, current literature and expert opinion and will examine prevalence of disease outcomes and predictors of those outcomes. The survey will be administered to IDUs in the two cities, which differ on the predominant type of heroin available. [unreadable] [unreadable] The three goals of this study are: 1) To examine the behaviors and belief systems related to use of specific types of heroin with particular attention to issues of risk and hygiene; 2) To examine the health related outcomes of specific heroin use; and 3) To determine the independent effects of specific types of heroin on health outcomes, i.e., soft tissue infection, HIV and heroin related overdose. [unreadable] [unreadable] [unreadable] [unreadable]